Cross-drilling attachment for automatic screw machines



Man: 20, 1923 1,449,172 (3. J. GENDREAU ET AL CROSS DRILLING ATTACHMENT FOR AUTOMATIC SCREW MACHINES Filed Dec 50, 1919 2 sheets-sheet 1 FIG. 1.

Mann 2@, 1923 11,449,172 c. J. GENDREAU ET AL CROSS DRILLING ATTACHMENT FOR AUTOMATIC SCREW MACHINES Filed Dec. 50, 1919 2 sheets-sheet 2 Ztl,

CHARLES J. GENDREAU AND JOHN SAISIVEY, 0E

MCEESTEPJ, HEW] YQRK, ASSIGNORS TO GENERAL BAELVVAY SEG-NAL COMPANY, EC'GHESTER, NE 1' YORK, A CORPO- RATION OF NEW YORK.

canes-DRILLING n'r'rncmrnnr non AUTUMATIC sonnw MAGHJINES.

Application filed December 30, 1919.

0 all whom it may concern:

Be it known that we, CHARLES J. GEN- nnicAU and JOHN L. SAnvnY, citizens of the United States, and residents of the city of llochester, in the county of Monroe and State of New York, have invented a new and useful Cross-Drilling Attachment for Automatic Screw Machines, of which the following is a specification.

This invention relates to improvements in automatic screw machines, and more particularly to a cross drilling mechanism or attachment for such machines, by means of which transverse holes inay be automatically drilled in the article or product as one of the regular operations of the machine.

It is found-in practice that if transverse holes are made in screw machine products, by a separate operation, the cost of manufacture is greatly increased, and in some instances, the cost of the drilling alone is as great as the entire cost of making the article on the screw machine.

It is desirable, therefore, to perform a cross drilling as one of the regular automatic operations of the machine; and theprimary object of our invention is to provide a simple and efiicient cross drilling mechanism which can be used to perform the drilling operation automatically as the article is being worked up on the screw machine and which will perform. this drilling operation quickly without delaying other operations.

A further object is to provide a cross drilling mechanism comprising few parts, and which may be used or not, as required, witiiout impairing the efficiency of the machine.

Other detail objects and advantages of the invention will be in part obvious and in part pointed out hereinafter.

ln describing the invention in detail, reference will be made to the acconipanyingdrawings, in which is illustrated one specific embodiment of our invention, in which like reference characters designate corresponding parts in the several views, and in which Figure 1 shows apartial outline of one type of an automatic screw machine, together with some of its operating parts, hav- Eerial No. 348,314.

g r th 311113088 ofillustrating the functions and operations of our invention, we have shown in the accompanying drawings one specific forn'i arranged to be applied to a multiple spindle screw machine of a Well known type; but it should be understood that by making appropriate changes in mechanical details, our invention may be applied. to other types and makes of screw machines. Since the construction and operation of automatic screw machines in general are well known, it has been deemedv unnecessary to show or describe many features of the construction. and. operation of such machines, attention being limited to those parts directly involved in the operation of our cross drilling mechanism.

The drilling mechanism, or so-called nent, coi'nprises in general a drill condriven by suitable means, preferably electrical motor. mechanism or feeding withdrawing the drill, and suitable clutch and brake devices for stopping and holdin the stock while the drilling is being done, ese parts being driven synchronously with the movement of the machine. Be- :"erring to the drawings. the drill l is mounted in a chuck 2 of the usual construction secured to the arn'iature shaft 3 of a suiwble electric motor M which is constantly opera .ed by current from some suitable source (not shown). This motor if is sup ported or. a cross slide 4 with connection permitting the n'iotor and the drill to be block 8 fixed at one end of the block 7 carries an adjusting; screw 9 which bears against the plate and thus provides means for moving thelmetor transversely of the cross slide 4. The cross slide t is guided in a bracket 10, such as-cominonly used on screw machines of this type, and this bracket is arranged in the usual way (not shown), so

that it may be adjusted lengthwise of the machine to permit holes to be drilled at the desired point in the stock.

Cross slide 4 has a pin 11 lined thereto which extends through a clearance slot in the'bra'cket and loosely through a hole in the upper end or a lever 12, said lever being journaled near its middle on a pin fas tened in the jaws of a fixed bracket 14. The lower end of the lever 12 carries a short fixed pin 1! which ooperates with a pair of cams 16 and 17 fastened to a plate 18 attached to the usual cam shaft 19 of the machine, so that. the lever 12 may be rocked and the cross slide t advanced and retracted in timed relation to the other operations the machine, in the manner more fully explained hereinafter. s

The clutch device for stopping rotation oi the stock comprises shifter 20 which is adapted to cooperate with two flanges on a clutch collar 21, commonly provided on each spindle of machines or the type illustrated. Themoveinent oi this clutch collar 21 lengthwise of the spindle S serves to connect and disconnect this spindle from the driving mechanism in the manner characteristic of this type of machine, thereby stopping; ro

tation of the spindle and stock. The clutch shifter20 is carried at the upper end of a movable lever 22 journaled near its middle on a pin 23 in a '1X8Cl bracket 24;, so that said lever 22 may swing lengthwise of the machine; The lower end of the lever 22 carries pin 25 cooperating with cam strips 26 and 27 on a cam dru 28 which is fastened to the main cam shaft 19.

The brake device for holding the spindles and the stock against rotation while the drilling is being done, comprises a br ke shoe 30 which cooperates with a flan collar 29 fastened to the spindle T brake shoefiltl is'preteii'ably provided with a friction lining of suitable material. The

brake shoe '30 is p otally connected to L I plunger 3i. (see 4), which is provid .Il

with an integral collar 32 slidably mounted in a recess in the upper end of a brake lever 34;. A compression spring 35 in the recess 33 bears against the collar 32 and presses the brake shoe 8O outward, the outward movement of the plunger 31 being lim ited by aejustable locking nuts The brake lever 34 is i'lilcrurned near its middle on a pin 37 secured two cars of the fixed bracket 24:, so that said lever may swing crosswise of the machine and move the brake shoe 30 toward and away from its cooperating collar 29. The lower end ofthe brake lever 34; is rounded and cooperates with a cam strip or ridge 38 fastened to the end of the cam drum 28 by bolts 39.

@peration The operation of the screw machine its it. being well known, needs no eX- planation. in multiple spindle machines of the type to which we have illustrated our in vention applied, the spindles are rotated or indexed the proper times to diilerent positions for performing different operations. in one oi"- these positions (see Fig. 2), the cross drilling operation performedby our improved inechanisin. flhe' parts have been shown in Figs. 1. and 3 in the positions which they assume just after the spindle S has been red, ready for the drilling operation. Taking up from this point the steps in the cycle oi the cross drilling operation, as the main 'can'i sh aft 19 revolves in the direction indicated by the arrow a, the beveled shoulder of the cam strip 26 engages pin 25 and shifts the clutch lever22 to throw clutch collar 21. out and dis-connect the driving: mechanism from the spindlefil. The lower end of the brake lever 34 now engages the curvedend of the camst'rip 38 and is thus swung out, pressing the brake shoe 30 against the collar 29 and quickly stoppingrotation of spindle S and firmly holding' it against n'iovement. The cam 16 on the plate 18 now engages the pin 15 on the lower end ;his ed e being relatively of the lever 12, and s I, abrupt, the lever 12 is rocked quickly, there by advancing cross slide 41-, together with the motor M and the drill 1 ca ried thereby, b 'up' the drill point the stock. Cross slide 4; and the drill 1 are now gradually advanced by the curved edge of the cam 16, this am beingsuitahly shaped to advance the drill. the appropriate rate. The

speed ot the drill and the rate at which it is .iied are, of course, selected so as to obtain the (piic est drill operation consistent. with wear on tlte drill, hardness of the stock and the like. When. the drilling is completed, the cam 17 picks up tie pin 15 and retracts and withdraws-i the drill. The

cross slide +2.- ram 17 is pref r this 1e; moven'ieut as rapid as practical. I connection it should be noted that the earns 16 and i? may have to be changed slightly in shape for the best results with different kinds of stock, difably sha ed so as to make 2 ferent sized holes, and the hire. After the drill is withdrawn, the brake operating lever 3% leaves the cam 38, and the spring lricks off the "brake shoe 30. The shoulder on the cam strip 27 new engages the pin 25 and rocks the clutch lever 22 to throw in the clutch. The cycle of the drilling operation is then completed, and the spindle S is then rotated by the indexing mechanism the usual way, and another spindle S '1 place, the clutch shifter 20 slipping between the flanges of the clutch collar 21 of the next spindle, and the brake shoe 3O likewise co operating with the collar on this next spindle, that everything is in position ready for the nextdrilling operation upon the stock carried by this next spindle.

lit will be evident that our improved cross chilling i'nerhanisn'i greatly decreases the cost of production of articles requiring the drilling of transverse holes therein, such j aw pins with cotter pin holes, and the like. The various cams controlling the operation of the cross drilling mechanism are shaped and adjusted in practice to obtain the eral steps in the cycle of the cross drilling operation in the proper sequence and without any intervening idle periods. The motor M driving the drill is preferably a variable speed motor of any of the well known types, in order that the speed of the drill may be varied to obtain the quickest and most effective drilling, i accorda e with the size and length of the hole and the character of the stock. To attain the most efiicicnt resul s it is evident that the time of operation of the cross drilling should be no longer than the time required for the longest operation upon the stock in-the other spindle positions, and we find that in most classes of worlr, this desirable result can be obtained, so that the cross drilling operation, being accomplished in an indented position of the spindle ca rier, which is commonly inactive, does not impair the efficiency or rapidity of the machine. Even where the other operations of the machine very simple and require a little less time than the cross drilling operation, there is still a great saving, because the cost of performing the cross drilling by a separate operation may be equal or even double the cost of shaping up the article. The drill is preferably driven by an electric motor, as

shown, rather than by a belt or the like, in'

order that the drill may be positively rotated as t is advztnced. Otherwise, with a belt drive, for example, the belt may slip and the drill being fed continuously, is lilrely to jan and break. Also, the use of. an electric motor for driving the drill obviates the difficulty of providing an etficient and reliable drive which will permit the necessary adjustn cut for spotting the drill correctly, and which will not interfere with the regular operations of the machine. ll hen the cross drilling mechanism is not needed, it may be readily thrown out of operation without interfei' with the rest of the machine.

L lbviously, various changes, additions or adaptations may be 11 ade in tie specific embodiment of our invention shown and described, and we desire to have it understood that this particular embodiment is merely illustrative of the idea means underlying our invention, and does not exhaust the various forms which may be advantageously employed in practice.

What we claim as new and desire to secure by Letters Patent of the United States, is:

l. A cross drilling mechanism for automatic screw machines comprising a drill adjustably mounted on a cross slide, an electric motor on the cross slide for driving the drill continuously in any of its adjusted positions and means for advancing and retracting said drill in synchronism with the regular operations of the machine.

2. A cross drilling mechanism for auton'iatic screw machines comprising a continuously driven electric drill mounted on a cross slide, and means for advancing and retract ing said slide in timed relation to the operating parts of the machine.

3. A cross drilling mechanism for auto matic screw machines comprising a drill mounted on a cross slide, an electric motor on the slide continuously driving the drill, for quickly advancing the drill to its drilling position, gradually feeding the drill, and then quickly retracting it, all in synchronism with the operating movements of the machine.

4. A cross drilling mechanism for automatic screw machines comprising a drill can ried by a cross slide, an electric motor on the slide continuously driving the drill, clutch and brake devices for stopping and holding the stock, and means for advancing and retracting the drill, said devices and means being operated in synchronism with the regular operations of the machine.

5. A cross drilling mechanism for automatic screw machines comprising a separate drill continuously driven by an electric motor adjustably mounted on a cross slid-e, means for stopping and holding the stock, and means for actuating said slide to advance, feed and retract the drill, the operation of both of said means being timed to occur at predetermined intervals in sequence with the regular operations of the machine.

6. in cross drill attachment for automatic screw machines comprising, a drill chuck and shaft adjustably mounted on a cross slide and adapted to receive drills of different sizes, a variable speed electric motor for positively and continuously driving the shaft in any one of its several adjusted positions, and means for advancing and re- Meeting the slide in synchronism" With the operation of the machine.

7. In av cross drill attachmentfor automatic screw machines comprising, a drill chuck and shaft mounted on a cross slide and adapted to receive drills of different sizes, a variable speed electric motor for positively and v continuously driving the shaft, and means for advancing and retracting the slide in synchronism with the operation of I the machine. 9

CHARLES J. GENDREAU. JOHN L. SARVEY. 

